Serious wheelchair accidents have risen to almost 37,000 per year. Users of power chairs are three times as likely to have accidents as users of manual chairs! Many people can neither walk nor successfully navigate a wheelchair, e.g., many with MS, quadraplegia, spinal stenosis, visual and other impairments. [unreadable] The Safety Sensing Independence-Enhancing Wheelchair (SIW) has the potential to reduce accident rates dramatically. Moreover, it could enable as many as 88,000 more non-ambulatory Americans to successfully use wheelchairs. [unreadable] During Phase I, we built SIW and safety sensor prototypes that met or exceeded all our goals. In Phase II, we will develop a research prototype of SIW with additional functionality. We will complete development of the 2 modes of assisted control: Assistive and One-Click. Manual Mode, in which the wheelchair operates like an ordinary power chair, was integrated in Phase I. For Assistive Mode, we will add redundant sensors to improve the SIW's ability to avoid obstacles at both head and body height. In One-Click mode, those needing the most assistance can travel to destinations, with a single click of an input device, as demonstrated in Phase I. During Phase II, we will continue to extend the capabilities of the localization and navigational algorithms using fuller modeling so that fine-tuning the wheelchair's position will become easier. [unreadable] During Phase II we will also finish development of the new lightweight more economical Safety Sensor tested successfully for head and stair sensing in Phase I. We will develop a Universal SIW User Interface to be compatible with nearly any type of input device, as recommended by Phase I feedback from Crotched Mountain Rehabilitation Center (CMRC) and from our 3.5 hour invited demonstration of the Phase I prototype at RESNA 2002. We will also integrate and test various types of seating, as recommended. We will plan assessment, build 3 more prototypes, and conduct lab, field and clinical trials in conjunction with CMRC during Phase II. The results of these trials will be used to design further independent trials and to prepare for the approval process in Phase III. [unreadable] Once SIW technologies are proven, ordinary chairs that allow users to accidentally drive down stairs will be considered highly unsafe. Moreover, allowing individuals to remain immobile, with no control over their own location, will be considered inhumane when the SIW is available to provide mobility at their command. [unreadable] [unreadable]